A dose of science | Is that you? Research finds that people with stronger immunity have higher "appearance"

"Wow, your immunity is so strong... The moonlight is so beautiful tonight."
——Natsume Soseki who read this paper

Star player Gu Ailing

Everyone loves beauty. Good-looking people, or attractive faces, always attract widespread attention. As the saying goes, "beauty is in the eyes of the beholder." The objective standard for measuring beauty has always been controversial, and it seems impossible for humans to reach a complete consensus.

However, it is well known that facial attractiveness is somewhat consistent across cultures. People who are attractive in one culture tend to be universally attractive in other cultures, despite the different emphases. This phenomenon suggests that humans judge the attractiveness of faces by observing some common biological indicators.

It is not clear what these indicators are.

A study published in the Proceedings of the Royal Society recently found a link between attractiveness and immunity, and they said the study was the most extensive and rigorous research on the topic to date.

The survey first took facial photos of 159 men and women (average age 20) and collected blood samples. When photographing faces in a fixed environment, the subjects were required to be bare-faced, with no sad or happy expressions, and not to take medication, do strenuous exercise, or drink alcohol before the photo was taken. Next, the researchers recruited 492 different men and women (average age 25), showed them 159 facial photos taken previously, and asked them to rate their attractiveness.

Combining data analysis, the researchers found that people who were rated more attractive had a higher rate of phagocytosis of E. coli bioparticles (p=0.042), higher basophil counts (p=0.004), lower neutrophil counts (p=0.043), and stronger NK cell cytotoxicity (p=0.033).

That is, the most attractive people were also the ones with the healthiest immune systems. The study found that the differences in attractiveness were only related to the two sexes. The most attractive men were those with highly active NK cells; the most desirable women were those whose blood had stronger antibacterial properties.

An NK cell is destroying cancer cells by mediating cytotoxicity

There was no relationship between higher levels of inflammation and attractiveness in the participants. This may be because any person's physical condition will temporarily decline under adverse circumstances, and facial attractiveness can transcend symptoms such as acute illness and is more likely to reflect a strong immune system. In short, the main role of facial attractiveness may not be to avoid a sick partner, but to avoid a partner who may affect the health of future offspring.

The researchers also found that, on average, female volunteers were more likely to find men with higher levels of NK cells in their blood attractive. Interestingly, the opposite was true for men: men were more likely to find women with lower levels of NK cells attractive. In fact, although NK cells can help fight viruses and tumors, high NK cell activity in women may be related to lower estrogen levels, lower fertility, and higher miscarriage rates.

Test results statistics

"Our ancestors evolved the ability to read the immune system from the face in order to survive in an infection-prone environment," the researchers said.

Human mate preferences were formed long before modern medicine, and modern humans may have overlooked the link between attractiveness and health. This also means that while attractiveness may have hinted at the health and immune function of ancestral groups, its link with health may no longer exist today, as modern medicine allows people with low immune function to survive relatively healthily. Perhaps those who have a strong tendency to "pay attention to appearance" retain a particularly strong instinct - to give their offspring better immunity!

References:

[1] Mengelkoch S, Gassen J, Prokosch ML, et al. More than just a pretty face? The relationship between immune function and perceived facial attractiveness[J]. Proceedings of the Royal Society B, 2022, 289(1969): 20212476.

Layout: Original Energy Cell-EAIS

Editor: Atomic Energy Cell-EAIS

Producer: Julie from Primal Cell